Method for replication between clouds, and system

Abstract

To replicate a cloud application.SOLUTION: A method implemented in a system includes: identifying a first cloud to be associated with a first node that communicates with an entity in scope of a terminal unit upon receipt of a first session establishment request signal from the terminal unit; starting communication between the first cloud and the terminal unit; and replicating cloud application data from the first cloud with which the terminal unit is communicating to another second cloud, with the replication conducted before the entity in scope of the terminal unit changes according to the transfer of the terminal unit.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a method and system for inter-cloud replication. [Background technology]

[0002] Multi-access Edge Computing (MEC) is being used in 5G communications. MEC is a technology that improves the real-time nature of data processing by placing computing resources such as servers and storage near the edge (terminals) of the mobile communications network and communicating within a unique network. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP TS23.501 V16.6.0 (2020-10) "5G; System architecture for the 5G System (5GS) (3GPP TS 23.501 version 16.6.0 Release 16)" Summary of the Invention [Problem to be solved by the invention]

[0004] 5.6.7.2 "Enhancement of UP path management based on the coordination with Afs" in Non-Patent Document 1 provides an overview of MEC operation. In the structure of 5G MEC, when a terminal device moves, the DNN (Data Network Name) assigned at the time of connection may change depending on the network to which it is connected. When the DNN is changed due to the movement of the terminal device, application data used in the cloud associated with the source DNN is replicated to the cloud associated with the destination DNN. When the application data is replicated to the destination cloud by cloud replication, the terminal device can use the destination cloud to use cloud services. However, in the past, the specific route of replication between clouds and PCC (Policy and Charging Control) have not been clarified. In addition, if the terminal device moves before the replication of the cloud application data is completed, the cloud application may not be available at the destination.

[0005] An object of the present invention is to provide replication between clouds. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, one aspect of the present disclosure is a method implemented in a system, comprising: in response to receiving a first session establishment request signal from a terminal device, identifying a first cloud associated with a first node communicating with an entity in which the terminal device is located; initiating communication between the first cloud and the terminal device; and replicating cloud application data from the first cloud with which the terminal device is communicating to a different second cloud, wherein the replication is performed before the entity in which the terminal device is located changes due to movement of the terminal device.

[0007] In order to solve the above-mentioned problems, one aspect of the present disclosure is a system comprising a session management node configured to, in response to a first session establishment request signal from a terminal device, identify a first cloud associated with a first node communicating with an entity in which the terminal device is located, and initiate communication between the identified first cloud and the terminal device, and replicate cloud application data from the first cloud with which the terminal device is communicating to another second cloud. [Brief description of the drawings]

[0008] [Figure 1] 1 illustrates a schematic diagram of a system for replicating cloud application data and resources, according to one embodiment of the present disclosure. [Diagram 2] FIG. 1 is a diagram illustrating an overview of a process for replicating application data and resources between clouds in a system according to one embodiment of the present disclosure. [Diagram 3] 3 illustrates a flow diagram of a process 300 for replicating cloud application data and resources used by an end device on a cloud before the end device moves, according to one embodiment of the present disclosure. [Figure 4] An example of the data structure of location information registered in the AMF memory unit according to one embodiment of the present disclosure is shown. [Diagram 5] 1 illustrates an example of a data structure of SMF device information registered in an SMF storage unit according to an embodiment of the present disclosure. [Figure 6] FIG. 13 is a diagram illustrating an overview of a process for performing real-time replication between clouds when a terminal device moves according to an embodiment of the present disclosure. [Figure 7] 13 illustrates a process flow for performing real-time replication between clouds when a terminal device moves according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Description of the embodiment of the present invention] First, the contents of the embodiment of the present invention will be listed and described. One embodiment of the present invention has the following configuration.

[0010] [Configuration 1] A characteristic configuration of a method for achieving the above-mentioned object is a method implemented in a system (100), which includes, in response to receiving a first session establishment request signal from a terminal device (102), identifying (S3) a first cloud 150 (#DNN_1) associated with a first node 130 (#UPF_1) that communicates with an entity in which the terminal device is located, initiating communication between the first cloud and the terminal device (S9), and replicating (S10) cloud application data from the first cloud with which the terminal device is communicating to another second cloud 150 (#DNN_2), wherein the replication is performed before the entity in which the terminal device is located changes due to movement of the terminal device.

[0011] [Configuration 2] Another characteristic configuration of the method disclosed herein is that the second cloud is connected to a second node (#UPF_2) other than the first node that communicates with an entity in which the terminal device is located.

[0012] [Configuration 3] Another characteristic configuration of the method according to the present disclosure is that the method further includes transmitting (S4) the policy control rule to each of the connected nodes (#UPF_1 to #UPF_N) of all clouds (#DNN_1 to #DNN_N) including the first cloud and the second cloud.

[0013] [Configuration 4] Another characteristic configuration of the method according to the present disclosure is that the first session establishment request signal from the terminal device includes a subscriber identification number assigned to the terminal device, and the policy control rule includes a policy control rule corresponding to the subscriber identification number.

[0014] [Configuration 5] Another characteristic feature of the method disclosed herein is that the policy control rule stipulates that, in response to a session establishment request signal from a terminal device, a cloud associated with an entity in which the terminal device resides is instructed to replicate to another cloud.

[0015] [Configuration 6] Another characteristic feature of the method of the present disclosure is that the replicating includes copying (S11) cloud application data from the first cloud associated with the entity in which the terminal device resides to all clouds other than the first cloud in accordance with the policy control rules.

[0016] [Configuration 7] Another characteristic configuration of the method of the present disclosure is that, when the entity in which the terminal device is located changes due to the movement of the terminal device (S12), the method further includes, in response to a second session establishment request signal from the terminal device, identifying an identifier of the second cloud associated with a second node (UPF_2) that communicates with the second entity in which the terminal device is located after the movement of the terminal device (S14).

[0017] [Configuration 8] Another characteristic configuration of the method according to the present disclosure is that the method further includes communicating between the second cloud and the terminal device (S16).

[0018] [Configuration 9] Another characteristic feature of the method disclosed herein is that it includes copying (S17) cloud application data from the second cloud associated with the entity in which the terminal device resides after the movement in accordance with the policy control rules to all clouds other than the second cloud.

[0019] [Configuration 10] Another feature of the method according to the present disclosure is that the entity is a base station and the terminal device moves between the base stations corresponding to different nodes.

[0020] [Configuration 11] Another feature of the method according to the present disclosure is that the entity is a mobility management node, and the terminal device moves between mobility management nodes corresponding to different nodes.

[0021] [Configuration 12] A characteristic configuration of a system for achieving the above-mentioned object is a system comprising a session management node, the session management node being configured to, in response to a first session establishment request signal from a terminal device, identify a first cloud associated with a first node communicating with an entity in which the terminal device is located (S3), and initiate communication between the first cloud and the terminal device (S9), and replicate cloud application data from the first cloud with which the terminal device is communicating to a different second cloud (S10).

[0022] [Details of the embodiment of the present invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the present disclosure is not limited to these examples, but is indicated by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included in the present disclosure. In the following description, the same elements in the description of the drawings will be given the same reference numerals, and redundant descriptions will not be repeated.

[0023] FIG. 1 illustrates a schematic diagram of a system 100 for replicating application data and resources of a cloud 150 according to an embodiment of the present disclosure. In the present disclosure, replication refers to copying application data and the like of a cloud 150 being used by a terminal device 102 to another cloud in order to ensure redundancy of data and the like of the cloud application. The system 100 is provided within a cloud-based mobile computing environment. In the system 100, even if the terminal device 102 moves to a different cloud 150, it is possible to continue using the cloud application being used at the destination.

[0024] Each entity shown in system 100 includes a network element that implements the main functions provided in system 100, such as mobility management, session management, policy control, subscriber profile management, and user plane functions. In addition to the illustrated network elements, other network elements may be used to implement some or all of the main functions of system 100. Also, in addition to the illustrated network elements, other network elements may be included.

[0025] In this embodiment, the system 100 is a system that complies with the 5th Generation (5G) standard, but is not limited to this example. The system 100 can be compliant with other communication standards such as the 4th Generation (4G) and the 6th Generation (6G). In the following, the system 100 will be described as being compliant with the 5G standard.

[0026] In the following, each entity constituting the system 100 shown in Fig. 1 will be described. In 5GC (5G core network), various network functions are defined as NFs (Network Functions) for each role. In Fig. 1, NFs 120 (Network Functions) are shown as multiple functional entities.

[0027] Examples of the NF 120 include an Access and Mobility Management Function (AMF) 122, a Session Management Function (SMF) 124, a Policy Control Function (PCF) 126, a Unified Data Repository (UDR) 128, and a User Plane Function (UPF) 130 shown in Fig. 1. Another example of the NF 120 is a Unified Data Management (UDM) (not shown). These NFs 120 are connected to a logical communication bus, and are further connected to a Network Exposure Function (NEF) 140. The NEF 140 is further connected to be able to communicate with a cloud 150. In this disclosure, these NFs 120 may be referred to as various devices in a core network.

[0028] In this example, the AMF 122 may be referred to as a mobility management node. The AMF 122 has a registration management function, a connection management function, a mobility management function of the terminal device 102, and the like. There may be a plurality of AMFs 122. The AMF 122 stores location information 400 of the terminal device 102 in a storage unit. Details of the location information 400 will be described later with reference to FIG. 4.

[0029] Under the AMF 122, there is a RAN 110 consisting of one or more base stations (BS) 104. The RAN 110 is a wireless access network consisting of antennas and base stations 104 ("gNB" in 5G). A first base station group (#BS_11 to #BS_1N) can be connected to a first UPF 130 (#UPF_1), a second base station group (#BS_21 to #BS_2N) can be connected to a second UPF 130 (#UPF_2), and an Nth base station group (#BS_N1 to #BS_NN) can be connected to an Nth UPF 130 (#UPF_N) (N is an arbitrary integer). Hereinafter, when there is no need to distinguish between the first UPF 130, the second UPF 130, and the Nth UPF 130, they may simply be referred to as UPF 130. The letters and numbers following the # of each device in FIG. 1 indicate examples of identifiers assigned to each device.

[0030] In this example, the SMF 124 may be referred to as a session management node. The SMF 124 manages and controls user data sessions. For example, it establishes, maintains, and releases data sessions. The SMF 124 can connect to the PCF 126 and one or more AMFs 122 (one in the illustrated example). The SMF 124 stores SMF device information 500 in a storage unit. Details of the SMF device information 500 will be described later with reference to FIG. 5.

[0031] In this example, the PCF 126 may be referred to as a policy control node. The PCF 126 provides a policy control function, and manages various policies on the network, such as allocating network resources, controlling quality, and applying security policies.

[0032] In this embodiment, the UDR 128 may be referred to as a subscriber data management node. The UDR 128 registers the subscriber database and status.

[0033] In this example, the UPF 130 may be referred to as a user plane function node. The UPF 130 is a component that forwards user data. It handles the forwarding of data sent or received by a user and supports low-latency and high-bandwidth communication. A plurality of UPFs 130 are connected under the SMF 124. In the example of FIG. 1, the first UPF 130 is assigned an identifier #UPF_1, the second UPF 130 is assigned an identifier #UPF_2, . . . the Nth UPF 130 is assigned an identifier #UPF_N. The UPFs 130 are connected to each other in a full mesh. Each UPF 130 enables a connection to a cloud 150 that is physically close, and can forward data from a cloud application to the terminal device 102. The UPF 130 is associated with an entity (base station 104, AMF 122) in which the terminal device 102 is located. When the entity in which the terminal device 102 is located is changed due to movement, the terminal device 102 is associated with a different UPF 130.

[0034] The NEF (Network Exposure Function) 140 is used to securely expose services, capabilities, etc. provided by the 3GPP network function (NF 120) to the outside (cloud 150). The NEF 140 may be referred to as an API providing device. In 5GC (5G core network), many of the control NFs for detecting user movement and controlling the setting and opening of data transfer paths that ensure quality such as required speed and delay time are made available from the outside via an API (Application Programming Interface). The NEF 140 (Network Exposure Function) provides this API. The NEF 140 supports the publication of capabilities and events, the secure provision of information from external applications to the 3GPP network, and the conversion of internal / external information. When the NEF 140 is accessed from the cloud 150 side, the control NF 120 can be controlled via the NEF 140.

[0035] The cloud 150 provides users with IT resources such as servers and storage, and applications over a network such as the Internet. By using the cloud 150, the system 100 can support various applications. A data network name (DNN) is used to identify data traffic to a cloud application via a mobile communication network. A different DNN is assigned to each cloud 150. In the example of FIG. 1, the first cloud 150 is assigned an identifier #DNN_1, the second cloud 150 is assigned an identifier #DNN_2, and so on to the Nth cloud 150. Hereinafter, when there is no need to distinguish between the first cloud 150, the second cloud 150, and the Nth cloud 150, they may simply be referred to as clouds 150. In addition, the UPF identifier and the cloud identifier are associated with each other on a one-to-one basis. The clouds 150 can be configured to be able to communicate with each other via the UPF 130.

[0036] The cloud 150 implements policy and charging control (PCC) rules for each subscriber identification number of the terminal device 102. Policy control sets the quality of service for users who use communication services and controls the network. For example, policy control includes limiting bandwidth to specific cloud applications, setting priorities, and applying security policies. Charging control also collects and controls charging information for the use of communication services.

[0037] Each of the multiple NFs 120, the NEF 140, and the cloud 150 may be implemented as one or more information processing devices. In another example, the multiple NFs 120, the NEF 140, and the cloud 150 may be implemented as software on a general-purpose server using virtualization technology.

[0038] The information processing device has hardware resources such as a control unit, a storage unit, and a communication unit. The control unit is realized by, for example, a computing means such as a CPU (processor). The control unit, the storage unit, and the communication unit are connected via a bus. The control unit is a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc. Specific examples of the storage unit are a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk, a flash memory, an optical disk, etc. The control unit of the information processing device is a functional unit that controls the operation and functions of the entire information processing device. The control unit of the information processing device realizes various processes in the information processing device by reading and executing various programs stored in the storage unit as necessary.

[0039] The terminal device 102 is a terminal used by a user who is a subscriber of a mobile communication service provider, and accepts various input operations by the user. The terminal device 102 is equipped with a SIM (Subscriber Identity Module), and is realized as, for example, a mobile terminal such as a smartphone, a PDA (Personal Digital Assistant), a tablet computer, or a laptop computer (a so-called notebook computer).

[0040] The terminal device 102 has hardware resources such as a control unit, a storage unit, a transmission / reception unit, an antenna, a SIM (Subscriber Identity Module), and an input / output unit. The control unit, the storage unit, the transmission / reception unit, the input / output unit, and the SIM are connected via a bus. The control unit is a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc. Specific examples of the storage unit are a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk, a flash memory, an optical disk, etc. The control unit of the terminal device 102 is a functional unit that controls the operation and functions of the entire terminal device 102. The control unit realizes various processes in the terminal device 102 by reading and executing various programs stored in the storage unit as necessary. The transmission / reception unit is a functional unit for wirelessly communicating with a base station device in an access network via an antenna. The input / output unit provides an interface (such as software buttons or physical buttons on a touch screen display) for a user to input information to the terminal device 102, and an interface (such as a touch screen display or a speaker) for outputting information from the terminal device 102.

[0041] A contract profile of a user who has a contract with a mobile communication carrier is stored in the SIM installed in the terminal device 102. The SIM contract profile stores subscriber information of the user, and includes individual identifier information such as a subscriber identification number (IMSI: International Mobile Subscriber Identity) assigned to a line contract of the terminal device, a telephone number of the subscriber user (MSISDN: Mobile Subscriber International Subscriber Directory Number), and a SIM card number (ICCID: Integrated Circuit Card Identifier).

[0042] First Embodiment Hereinafter, with reference to FIG. 1, an outline of a process of copying a policy and charging control (PCC) rule of the cloud 150 to the UPF 130 under the SMF 124 will be described. Then, with reference to FIG. 2, an outline of a process of replicating the cloud after copying the PCC rule will be described. The PCC rule specifies policy management, traffic management, session management, etc. in a mobile communication network. In the present disclosure, the PCC rule can specify a replication rule and a method of downloading the PCC rule. A series of processes shown in FIG. 1 and FIG. 2 are performed before the terminal device 102 moves between entities (in this example, the base station 104) connected to different UPFs 130. In FIG. 1 and FIG. 2, dotted arrows indicate the flow of the process.

[0043] 1 shows an overview of the process of registering the PCC rule set in the cloud 150 to the UPF 126 and the SMF 124 in the system 100, and the process from when the terminal device 102 transmits a session establishment request signal to the base station 104 to when the PCC rule is copied to the UPF 130 under the SMF 124 and when the terminal device 102 starts communication with the cloud 150. The clouds 150 each set PCC rules corresponding to the subscriber identification numbers of all subscribers of the mobile communication carrier.

[0044] 1, PCC rules corresponding to the subscriber identification numbers of all subscribers of the mobile carrier are transmitted from the cloud 150 to the PCF 126 and the SMF 124 via the NEF 140 and the UDR 128, and are registered in the SMF 124. The PCC rules may be registered in the PCF 124.

[0045] Next, in S2, the terminal device 102 transmits a session establishment request signal to the SMF 124 via the base station 104 and the AMF 122.

[0046] Next, in S3, in response to receiving the session establishment request signal, the SMF 124 reads out the PCC rule associated with the subscriber identification number of the terminal device 102 from the registered PCC rules. The SMF 124 also identifies the identifier (e.g., #UPF_1) of the UPF 130 associated with the terminal device 102. "#UPF_1" is the UPF 130 that is located physically close to the terminal device 102.

[0047] Next, in S4, the SMF 124 transmits the read PCC rule of the terminal device 102 to all UPFs 130 (#UPF_1, #UPF_2, and #UPF_3) that are under the control of the SMF 124 and connected to each cloud 150 (#DNN_1, #DNN_2, and #DNN_3).

[0048] Next, in S5, all UPFs 130 connected to the cloud 150 under the control of the SMF 124 register the received PCC rule. Furthermore, upon registering the PCC rule, each UPF 130 transmits an acknowledgment to the SMF 124 indicating that registration of the PCC rule has been completed.

[0049] Next, upon receiving a positive response from each UPF 130, in S6, the SMF 124 sends a replication instruction to the cloud 150 (in this example, "#DNN_1") associated with the UPF 130 (#UPF_1) identified in S3. The cloud 150 (#DNN_1) may be a cloud located physically close to the identified UPF 130 connected to the residing entity.

[0050] At S7, the cloud 150 associated with the identified UPF 130 ("#DNN_1" in this example) sends an acknowledgement to the SMF 124 indicating receipt of the replication instruction.

[0051] Next, upon receiving an acknowledgement from the cloud 150 associated with the identified UPF 130, the SMF 124 transmits a communication start instruction to the terminal device 102 in S8.

[0052] Upon receiving the communication start instruction, in S9, the terminal device 102 can start communication with the cloud 150 that is capable of communicating with the identified UPF 130 (#UPF_1 in this example) and is physically close to the terminal device 102.

[0053] Conventionally, after the SMF 124 determines that the terminal device 102 has moved, the SMF 124 transmits the PCC rule to the UPF 130. According to the present disclosure, before the terminal device 102 moves, the PCC rule can be registered in the SMF 124 and all UPFs 130 under the SMF 124 in accordance with a session establishment request from the terminal device 102. According to the present disclosure, for example, before the terminal device 102 starts communication with a cloud application provided by the first cloud 150 that is physically close, the PCC rule can be registered in advance in the UPFs 130 under the SMF 124 in response to a session establishment request signal from the terminal device 102.

[0054] FIG. 2 is a diagram showing an overview of a process for replicating application data and resources between clouds in a system 100' according to an embodiment of the present disclosure. FIG. 2 shows a process following FIG. 1. The numbers of each process are consecutive numbers following FIG. 1. The system 100 shown in FIG. 1 and the system 100' shown in FIG. 2 have the same network configuration, and redundant descriptions of each element will not be repeated. Below, an overview of a process for replicating data to a cloud other than the cloud with which the terminal device 102 is communicating before the terminal device 102 moves will be described with reference to FIG. 2.

[0055] 2, data and resources for replication are read out from the cloud 150 ("#DNN_1" in this example) in communication with the terminal device 102, and are created as replication data. The data and resources for replication are various data and resources that the user is using in the cloud 150 via the terminal device 102. The data and resources for replication may include, for example, various data such as various documents, emails, schedules, social media data, images, videos, etc. that the user is using in the cloud 150 by the terminal device 102.

[0056] Next, in S11, the first cloud 150 (#DNN_1) communicating with the terminal device 102 transmits the created replication data to all other clouds 150 ("#DNN_2" to "#DNN_N") via the UPF 130 (#UPF_1) to perform replication. Specifically, according to the policy control rule received by the UPF 130 connected to all clouds, respectively, the cloud application data from the first cloud associated with the entity in which the terminal device is present is copied to all clouds other than the first cloud. This allows data and resources to be shared among all clouds 150. Even if the terminal device 102 moves between different clouds 150 (between UPFs 130), the terminal device 102 can continue to use the cloud application by using another cloud 150.

[0057] Conventionally, the specific route of replication between clouds has not been clearly defined. According to the present disclosure, the specific route of replication between clouds is shown.

[0058] Furthermore, conventionally, when the movement of the terminal device 102 is detected, the cloud application is replicated after the movement is detected. For this reason, if the cloud application is not completed while the terminal device 102 is moving, the cloud application may not be continuously used. According to the present disclosure, before the terminal device 102 moves, the terminal device 102 makes a session establishment request and starts communication, and then application data of the cloud 150 communicating with the terminal device 102 is replicated to all other clouds 150. For this reason, even if the terminal device 102 moves, the terminal device 102 can continuously use the cloud application.

[0059] Fig. 3 shows a flow of a process 300 for replicating cloud application data and resources used by the terminal device 102 on the cloud before the terminal device 102 moves, according to an embodiment of the present disclosure. Fig. 3 shows details of the process shown in Fig. 1 and Fig. 2. Steps S302 to S320 in Fig. 3 correspond to S1 to S9 in Fig. 1, and steps S322 to S326 in Fig. 3 correspond to S10 and S11 in Fig. 2.

[0060] First, in step S302 (corresponding to "S1" in FIG. 1), PCC rules corresponding to all subscriber identification numbers are transmitted from an arbitrary cloud 150 (any of #DNN_1 to #DNN_N) to a PCF 126 (Policy Control Function) via the NEF 140 and the UDR 128. The PCC rules are then transmitted from the PCF 126 to the SMF 124.

[0061] All clouds 150 (#DNN_1 to #DNN_N) register a common PCC rule. Therefore, the PCC rule registered in any of the clouds 150 only needs to be transmitted to the SMF 124 and PCF 126. In this example, the PCC rule of cloud 150_N (#DNN_N) is transmitted. Since it is not known which cloud 150 the terminal device 102 is under, the PCC rule can be registered from any cloud 150.

[0062] The PCC rule can be set for each subscriber identification number of the terminal device 102. In the present disclosure, the PCC rule can stipulate that, in a mobile network environment, when the terminal device 102 requests to establish a session, the cloud 150 associated with the entity in which the terminal device 102 resides is instructed to replicate data and resources of a cloud application to another cloud.

[0063] Conventionally, the PCC rules for performing replication between clouds have not been clearly defined. According to the present disclosure, the PCC rules for performing replication between clouds are clarified.

[0064] Next, in step S304, the PCF 126 and the SMF 124 register the PCC rule received from any one of the clouds 150 in their respective storage units.

[0065] Next, in step S306 (corresponding to "S2" in FIG. 1), when the terminal device 102 accesses a cloud application, it transmits a session establishment request signal to the SMF 124 via the base station 104 and the AMF 122. The session establishment request signal transmitted from the AMF 122 to the SMF 124 may include the subscriber identification number of the terminal device 102 and an identifier (#BS_11 in this example) assigned to the entity (base station 104 in this example) in which the terminal device 102 is located.

[0066] Furthermore, in step S306, the AMF 122 identifies an identifier (#BS_11 in this example) assigned to an entity in which the terminal device 102 resides, in response to the session establishment request signal received from the terminal device 102 via the base station 104. The AMF 122 refers to the location information 400 stored in the storage unit, and identifies an identifier (#UPF_1 in this example) assigned to the UPF 130 associated with the location entity (#BS_11) of the terminal device 102.

[0067] 4 illustrates an example of a data structure of the presence information 400 registered in the storage unit of the AMF 122 according to an embodiment of the present disclosure. The presence information 400 includes items of identifiers (BS_11 to BS_NN) of all subordinate base stations 104 and items of identifiers (#UPF_1 to #UPF_N) assigned to the UPFs 130 associated with each base station 104. In the presence information 400, each presence entity is associated in advance with a UPF 130 that is physically close. The presence information 400 allows the AMF 122 to know which UPF 130 the base station 104 is associated with. The identifier of one UPF 130 is assigned to the identifier of each base station 104. Also, the identifier of one UPF 130 can be assigned to the identifier of one or more base stations 104.

[0068] Next, in step S308 (corresponding to "S3" in FIG. 1), in response to a session establishment request signal from the AMF 122, the SMF 124 refers to the SMF device information 500 stored in the storage unit, and identifies a cloud identifier (#DNN_1) associated with an identifier (#UPF_1 in this example) assigned to the identified UPF 130. After registering the PCC rule, the terminal device 102 can use the resources of the cloud 150 corresponding to the identified cloud identifier.

[0069] 5 illustrates an example of a data structure of SMF device information 500 registered in a storage unit of the SMF 124 according to an embodiment of the present disclosure. The SMF device information 500 includes items of identifiers (#UPF_1 to #UPF_N) of all UPFs 130 to which the SMF 124 connects, and items of identifiers (#DNN_1 to #DNN_N) assigned to clouds 150 associated with each UPF. The SMF device information 500 allows the SMF 124 to know which cloud 150 the UPF 130 is associated with. The terminal device 102 can use the cloud identifier to connect to a cloud application and use resources in the cloud 150.

[0070] Next, in step S310 (corresponding to "S4" in Fig. 1), the SMF 124 simultaneously transmits the PCC rule associated with the subscriber identification number of the terminal device 102 to all UPFs 130 (#UPF_1 to #UPF_N) connected to the cloud 150. As shown in Fig. 3, in step S310, the SMF 124 can simultaneously transmit the PCC rule to each UPF (#UPF_1 to #UPF_N).

[0071] Next, in step S312 (corresponding to "S5" in FIG. 1), each UPF 130 (#UPF_1 to #UPF_N) stores the received PCC rule in its respective storage unit. Then, each UPF 130 (#UPF_1 to #UPF_N) transmits a notification to the SMF 124 that registration of the PCC rule has been completed. Before the terminal device 102 starts communication with the cloud 150 (#DNN_1), the PCC rule of the terminal device 102 is registered in advance in all UPFs 130. Note that in FIG. 1, the processes of steps S310 and S312 for the other UPFs 130 (identifiers #UPF_2 to #UPF_N-2) are the same as the processes for the first UPF 130 (identifier #UPF_1), and therefore will not be described.

[0072] Next, upon receiving a notification of completion of registration of the PCC rule, the SMF 124 applies the PCC rule associated with the subscriber identification number of the terminal device 102 in step S314 (corresponding to "S6" in FIG. 1). The PCC rule specifies that the first cloud (#DNN_1) associated with the entity in which the terminal device 102 resides is instructed to replicate to other clouds. In accordance with the PCC rule, the SMF 124 transmits an instruction to the first cloud 150 (#DNN_1) associated with the entity in which the terminal device 102 resides, via the PCF 126, the UDR 128, and the NEF 140, to replicate to other clouds 150 (#DNN_2 to #DNN_N).

[0073] Conventionally, after the SMF 124 detects the movement of the terminal device 102, the SMF 124 notifies the cloud before the movement of the communication target that the terminal device has moved to another UPF. In response to this notification, replication is performed between the cloud before the movement and the cloud of the movement destination. However, if the terminal device 102 moves between UPFs before the replication is completed, the terminal device 102 may not be able to communicate with the cloud of the movement destination. According to the present disclosure, instead of notifying the cloud during communication of the movement of the terminal device, the SMF 124 identifies the cloud of the communication target upon receiving a session establishment request signal from the terminal device 102 before the movement of the terminal device 102, and transmits a replication instruction to another cloud to the identified cloud, that is, the cloud (#DNN_1) associated with the entity in which the terminal device 102 resides.

[0074] Next, in step S316 (corresponding to "S7" in FIG. 1), the cloud 150 (#DNN_1) transmits an acknowledgment to the effect that the cluster replication instruction has been received to the SMF 124 via the NEF 140, the UDR 128, and the PCF 126.

[0075] Next, in step S318 (corresponding to “S8” in FIG. 1), the SMF 124 transmits a communication start instruction to the terminal device 102 via the AMF 122 and the base station 104.

[0076] Upon receiving the communication start instruction, in step S320 (corresponding to "S9" in Figure 1), the terminal device 102 starts communication with the first cloud 150 (#DNN_1) via UPF 130 (#UPF_1) associated with the entity in which the terminal device 102 is located (in this example, #BS_11).

[0077] Next, in step S322 (corresponding to "S10" in Figure 2), the first cloud 150, upon starting communication with the terminal device 102, reads out the cloud application data in use from the memory unit of the first cloud 150, creates it as replication data, and also sends a replication start instruction to the UPF 130.

[0078] Next, in step S324 (corresponding to "S11" in FIG. 2), when the UPF 130 receives a replication start instruction from the first cloud 150 (#DNN_1), the UPF 130 reads the PCC rule and replicates the replication data between the first cloud 150 (#DNN_1) associated with the entity in which the terminal device 102 resides and all other clouds 150 (#DNN_2 to #DNN_N) according to the PCC rule. For example, as shown in the figure, the first cloud 150 transmits the replication data to the second cloud 150 (#DNN_2) via the first UPF 130 and the second UPF 130, and the second cloud copies the received replication data. Alternatively, the first cloud 150 transmits the replication data to the Nth cloud 150 (#DNN_N) via the second UPF 130 and the Nth UPF 130, and the Nth cloud copies the received replication data.

[0079] Next, in step S326, all other clouds 150 store the received replication data in their respective storage units.

[0080] As described above, in the cloud 150, data and resources being used by the terminal device 102 are transmitted to and copied to each of the other clouds 150 (#DNN_2 to #DNN_N) via the UPF 130 (#UPF_1) associated with each first cloud 150 (#DNN_1). When the replication is completed, the other clouds 150 (#DNN_2 to #DNN_N) transmit a completion notification to the first cloud 150 (#DNN_1) that is the transmission source.

[0081] Conventionally, when the SMF 124 detects the movement of the terminal device 102 between UPFs 130, it performs replication of data and resources of cloud applications. For this reason, if the terminal device 102 communicates with the UPF 130 after the movement before the replication is completed, the terminal device 102 may not be able to continue using the application. According to the present disclosure, cloud replication is performed when a session establishment request signal is sent from the terminal device 102 before the movement of the terminal device 102.

[0082] FIG. 6 is a diagram showing an overview of a process for performing real-time replication between clouds when a terminal device 102 in a system 100'' moves according to an embodiment of the present disclosure. FIG. 6 shows a process following FIG. 2, and the numbers of each process are consecutive numbers following FIG. 2. The system 100 shown in FIG. 1, the system 100' shown in FIG. 2, and the system 100'' shown in FIG. 3 have the same network configuration, and overlapping descriptions of each element will not be repeated. In this example, it is assumed that the terminal device 102 moves between base stations under the same AMF.

[0083] In S12, the terminal device 102 moves from the first UPF 130 (#UPF_1) to the second UPF 130 (#UPF_2).

[0084] Next, in S13, the terminal device 102 transmits a session establishment request signal to the SMF 124 via the base station 104 (#BS_21) that is closest to the position after the movement and the AMF 122 connected to this base station.

[0085] Next, in S14, in response to acquiring the session establishment request signal, the SMF 124 reads out the PCC rule associated with the subscriber identification number of the terminal device 102. In addition, the SMF 12 identifies the UPF 130 identifier (#UPF_2) associated with the entity in which the terminal device 102 resides after the movement.

[0086] Next, in S15, the SMF 124 sends an acknowledgment to the terminal device 102.

[0087] Next, in S16, the terminal device 102 switches communication from the first cloud 150 to the second cloud 150 with which it will communicate after the move.

[0088] Next, in S17, the second cloud 150 transmits data related to the cloud application to the other clouds 150 in real time and updates the cloud application data. By updating, all clouds 150 share the cloud application data in real time. In addition, all UPFs 130 have a common PCC rule for the terminal device 102. Therefore, no matter which cloud 150 (#DNN_1 to #DNN_N) the terminal device 102 moves to, the PCC rule held by the UPF 130 can be applied and the terminal device 102 can continue to use the application of the cloud 150 (#DNN_1) associated before the movement of the terminal device 102.

[0089] Fig. 7 shows a flow of a process 700 for performing real-time replication between clouds when the terminal device 102 moves according to an embodiment of the present disclosure. Details of the process shown in Fig. 6 will be described below with reference to Fig. 7. Steps S704 to S708 in Fig. 7 correspond to S12 to S14 in Fig. 6, and step S712 in Fig. 7 corresponds to S15 in Fig. 6.

[0090] First, as shown in step S702, before the terminal device 102 moves, the terminal device 102 communicates with the first cloud 150 (#DNN_1) via the UPF 150_1 (#UPF_1).

[0091] Next, in step S704 (corresponding to "S12" in FIG. 6), the terminal device 102 moves between UPFs 130. In this example, it is assumed that the terminal device 102 moves from a base station 104 (#BS_11) corresponding to a first UPF (#UPF_1) to a base station 104 (#BS_21) corresponding to a second UPF (#UPF_2).

[0092] Next, in step S706 (corresponding to "S13" in FIG. 6), when the terminal device 102 accesses the cloud application, it transmits a session establishment request signal to the SMF 124 via the second base station 104 (#BS_21) and the AMF 122. The session establishment request signal transmitted from the AMF 122 to the SMF 124 may include the subscriber identification number of the terminal device 102 and an identifier (#BS_21 in this example) assigned to the entity in which the terminal device 102 resides after moving.

[0093] In step S706, the AMF 122 identifies an identifier (#BS_21 in this example) assigned to an entity in which the terminal device 102 after moving resides, in response to a session establishment request signal received from the terminal device 102 via the base station 104. Furthermore, the AMF 122 refers to the location information 400 stored in the storage unit, and identifies a UPF 130 identifier (#UPF_2 in this example) associated with the location entity identifier (#BS_21) of the terminal device 102. "#UPF_2" is a UPF 130 located physically close to the terminal device 102 after moving.

[0094] Next, in step S708 (corresponding to "S14" in FIG. 6), the SMF 124 can determine that the terminal device has moved if the location identifier (#BS_21 in this example) of the session establishment request signal received in step S704 is different from the location identifier (#BS_11 in this example) of the session establishment request signal received immediately before. In addition, the SMF 124 may refer to the SMF device information 500 stored in the storage unit in response to the session establishment request signal from the terminal device after the movement, and identify the cloud identifier (#DNN_2) associated with the identified UPF 130 identifier.

[0095] Next, in step S710 (corresponding to "S15" in Figure 6), the SMF 124 transmits an acknowledgment to the terminal device 102 in response to receipt of the session establishment request signal to the terminal device 102 via the entity (AMF 122, base station 104 (#BS_21)) in which the terminal device 102 is located after the movement.

[0096] Next, in step S712 (corresponding to "S16" in FIG. 6), the terminal device 102 connects to the second cloud 150 (#DNN_2) communicatively connected to the UPF 130 via the base station 104 (#BS_21) and the second UPF 130 (#UPF_2) communicatively connected to the base station 104. The cloud application has already been replicated in the second cloud 150 (#DNN_2) after the move (FIG. 3, step S326). Therefore, the terminal device 102 can continue to use the cloud application even after the move.

[0097] Next, in step S714 (corresponding to "S17" in FIG. 6), the second cloud with which the terminal device 102 is communicating replicates cloud applications to all other clouds. As an example, the second UPF 130 (#UPF_2) reads the PCC rule, and replicates replication data between the second cloud 150 (#DNN_2) associated with the entity in which the terminal device 102 resides and all other clouds 150 (#DNN_1, #DNN_3 to #DNN_N) according to the PCC rule. For example, the second cloud 150 transmits the replication data to the first cloud 150 via the second UPF 130 (#UPF_2) and the first UPF 130 (#UPF_1). In addition, the second UPF 130 may read the PCC rule in accordance with a replication start instruction that the SMF 124 has previously transmitted to the second cloud (#DNN_2) identified by the SMF 124.

[0098] Next, in step S716 (corresponding to "S17" in FIG. 6), all other clouds 150 store the received replication data in their respective storage units.

[0099] This allows cloud applications to be shared and updated across all clouds, and the replication of cloud applications is performed in real time.

[0100] <Second embodiment> The above describes the processing when the terminal device 102 moves between base stations under the same AMF 122. According to the second embodiment of the present disclosure, the terminal device 102 can also perform replication of cloud applications when moving between AMFs. The processing when the terminal device 102 moves between AMFs is substantially the same as the processing when the terminal device 102 moves between base stations under the same AMF 122. Therefore, hereinafter, the same processing will not be described.

[0101] 3, the AMF 122 identifies the identifier (#AMF_1) of the entity in which the terminal device 102 resides, in response to a session establishment request signal received from the terminal device 102. The residency information 400′ includes an item of the identifier of each AMF 122 and an item of the identifier assigned to the UPF 130 associated with each AMF 122.

[0102] In a step corresponding to step S320 in FIG. 3, the terminal device 102 starts communication with the first cloud 150 (#DNN_1) via the UPF 130 (#UPF_1) associated with the entity (in this example, #AMF_1) in which the terminal device 102 resides.

[0103] 7, the terminal device 102 moves between UPFs 130. In this example, it is assumed that the terminal device 102 moves from a first AMF 122 (#AMF_1) corresponding to a first UPF (#UPF_1) to a second AMF 122 (#AMF_2) (not shown) corresponding to UPF_2.

[0104] In a step corresponding to step S706 in FIG. 7, when the terminal device 102 accesses a cloud application, the terminal device 102 transmits a session establishment request signal to the SMF 124 via the base station 104 and the second AMF 122 (#AMF_2). The session establishment request signal transmitted from the AMF 122 to the SMF 124 can include the subscriber identification number of the terminal device 102 and an identifier (#AMF_2 in this example) assigned to the entity in which the terminal device 102 is located after the movement. The SMF 124 determines that the terminal device has moved when the in-service identifier (#AMF_2 in this example) of the session establishment request signal received in step S704 is different from the in-service identifier (#AMF_1 in this example) of the session establishment request signal received immediately before. In addition, the SMF 124 specifies the second UPF 130 (#UPF_2) that communicates with the entity in which the terminal device is located after the movement in response to the session establishment request signal from the terminal device after the movement.

[0105] Although the embodiment of the present invention has been described above, the above-mentioned embodiment of the invention is intended to facilitate understanding of the present invention and does not limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention naturally includes equivalents thereof. Furthermore, within the scope of solving at least a part of the above-mentioned problems or achieving at least a part of the effects, any combination of the embodiments and modifications is possible, and any combination or omission of each component described in the claims and specification is possible. [Explanation of symbols]

[0106] 100…System 102...Terminal device 104...Base station 122...AMF 124...SMF 126…PCF 128...UDR 140…NEF 150…Cloud 400…Area information 500…SMF device information

Claims

1. 1. A method implemented in a system, comprising: In response to receiving a first session establishment request signal from a terminal device, identifying a first cloud associated with a first node that communicates with an entity in which the terminal device is located; Initiating communication between the first cloud and the terminal device; replicating cloud application data from the first cloud to a second cloud with which the terminal device is in communication; wherein the replication is performed before an entity that the terminal device is present in changes due to movement of the terminal device.

2. The method of claim 1 , wherein the second cloud is connected to a second node separate from the first node that communicates with an entity in which the terminal device is located.

3. The method comprises: The method of claim 1 , further comprising: transmitting a policy control rule to each of the nodes connected to all clouds, including the first cloud and the second cloud, respectively.

4. the first session establishment request signal from the terminal device includes a subscriber identification number assigned to the terminal device; The method of claim 3 , wherein the policy control rules include a policy control rule that corresponds to the subscriber identification number.

5. The policy control rule is: The method according to claim 4 , further comprising the step of: instructing a cloud associated with an entity in which the terminal device resides to perform replication to another cloud in response to a session establishment request signal from the terminal device.

6. The replicating step comprises:

6. The method of claim 5, further comprising copying cloud application data from the first cloud associated with the entity in which the terminal device resides to all clouds other than the first cloud in accordance with the policy control rules.

7. The method comprises: When the entity in which the terminal device is located changes due to the movement of the terminal device, The method according to claim 1 , further comprising: determining, in response to a second session establishment request signal from the terminal device, an identifier of the second cloud associated with a second node that communicates with a second entity in range after the terminal device moves.

8. The method comprises: The method of claim 7 , further comprising communicating between the identified second cloud and the terminal device.

9. 9. The method of claim 8, further comprising copying cloud application data from the second cloud associated with an entity to which the terminal device is present after the movement to all clouds other than the second cloud in accordance with policy control rules.

10. The method of claim 7 , wherein the entities are base stations and the terminal device moves between the base stations corresponding to different nodes.

11. The method of claim 7 , wherein the entity is a mobility management node, and the terminal device moves between mobility management nodes corresponding to different nodes.

12. 1. A system comprising a session management node, The session management node includes: In response to a first session establishment request signal from a terminal device, identifying a first cloud associated with a first node that communicates with an entity in which the terminal device is located; initiating communication between the first cloud and the terminal device; A system that replicates cloud application data from the first cloud with which the terminal device is in communication to a second cloud.

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